/Engine/Source/Runtime/Core/Public/Delegates/DelegateInstancesImplFwd.h
TWeakBaseFunctorDelegateInstance< UserClass, RetValType(ParamTypes...), UserPolicy, FunctorType, VarTypes... >
template<typename UserClass, typename FuncType, typename UserPolicy, typename FunctorType, typename... VarTypes> class TWeakBaseFunctorDelegateInstance